<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>按钮</title>
</head>

<body>
  <!-- form 表单区域 -->
  <!-- action="" 发送数据的地址 -->
  <form action="">
    用户名：<input type="text">
    <br><br>
    密码：<input type="password">
    <br><br>

    <!-- 如果省略 type 属性，功能是 提交 -->
    <button type="submit">提交</button>
    <button type="reset">重置按钮</button>
    <button type="button">普通按钮</button>
  </form>
</body>

</html>